Antimicrobial Activity of 4-Chlorocinnamic Acid Derivatives.

The microbial resistance of fungi and bacteria is currently considered a major public health problem. Esters derived from cinnamic acid have a broad spectrum of pharmacological properties that include antimicrobial activity. In this study, a collection of structurally related 4-chlorocinnamic acid esters was prepared using Fischer esterification reactions, alkyl or aryl halide esterification, and Mitsunobu and Steglich reactions. All of the esters were submitted to antimicrobial tests against strains of the species Candida albicans, Candida glabrata, Candida krusei, Candida guilliermondii, Pseudomonas aeruginosa, and Staphylococcus aureus. The compounds also were subjected to molecular docking study with the enzyme 14α-demethylase. Twelve esters derived from 4-chlorocinnamic acid were obtained, with yields varying from 26.3% to 97.6%, three of which were unpublished. The ester methyl 4-chlorocinnamate (1) presented activity against S. aureus at the highest concentration tested. In the antifungal evaluation, all of the esters were bioactive, but methoxyethyl 4-chlorocinnamate (4) and perillyl 4-chlorocinnamate (11) were the most potent (MIC = 0.13 and 0.024 µmol/mL, respectively). The data of molecular docking suggested that all the compounds present good affinity towards the active site related to antifungal activity. Therefore, the esters tested may be inhibitors of the enzyme 14α-demethylase. In addition, the results demonstrate that substituents of short alkyl chains with presence of heteroatom, such as oxygen, or those with a perillyl type terpenic substructure promote better antifungal profiles.

Secondary hemostasis studies of crude venom and isolated proteins from the snake Crotalus durissus terrificus.

Among the activities triggered by Crotalus durissus terrificus snake venom, coagulation is intriguing and contradictory since the venom contains both coagulant and anticoagulant precursor proteins. This work describes the in vitro effects of crude venom and purified proteins from snake Crotalus durissus terrificus as they affect coagulation factors of clotting pathways. Coagulant and/or anticoagulant activities of crude venom, and purified proteins were all analyzed directly in human plasma. Clots formed by crude venom and Gyroxin presented as flexible hyaline masses in punctiform distribution. Clot formation time evaluation of isolated proteins with PT and APTT assays made it possible to infer that these proteins interfere in all coagulation pathways. However, regarding ophidism by C. d. terrificus, Gyroxin acts directly, breaking down fibrinogen to fibrin and increasing the amount plasminogen activator, which results in the formation of thrombi. Crotoxin complex, Crotoxin A and Crotoxin B proteins can act in prothrombinase complex formation; Crotoxin B can inhibit prothrombinase complex formation by direct interaction with Factor Xa. Crotamine interacts with negatively charged regions of differing coagulation factors in all coagulation pathways, and possesses a whole set of activities causing dysfunction, activation and/or inhibition of natural anticoagulants and disturbing hemostasis.

Proteomic of goat milk whey and its bacteriostatic and antitumour potential.

Goat whey is normally discarded in the milk processing industry. However, several studies have addressed its biological properties and possible use in human or animal diet. The present study aimed to analysis the protein profile of goat whey to evaluate its possible oxidant, antioxidant, antibacterial, antitumour, and cytotoxic activities in vitro against human erythrocytes. Goat whey was skimmed, and crude protein extract (CPE) was obtained. Next, protein fractions (F) were obtained using ammonium sulphate precipitation method. The proteins were characterized by SDS-PAGE, two-dimensional electrophoresis and soluble protein measurements. No significant differences were observed in protein profile of CPE, F 30-60% and F 60-90%. The highest protein content was found in F 60-90% (0.41mgP/mL). All samples, except F 0-30% showed bacteriostatic activity against different bacterial strains. Only CPE at a concentration of 1000µg/mL was haemolytic against human erythrocytes. Oxidant activity against erythrocytes was not observed. Antioxidant activity was observed only for CPE. Cytotoxicity against C6 rat glioma cell line that was performed with CPE revealed tumour cell death>70% at concentrations of 0.05 and 0.1µg/mL. These results demonstrate at first time that CPE may be used as an antioxidant, bacteriostatic and cytotoxic compound against tumour cells.

Brown Algae Padina sanctae-crucis Børgesen: A Potential Nutraceutical.

Padina sanctae-crucis Børgesen is distributed worldwide in tropical and subtropical seas; belongs to the Dictyotaceae family, and has proven to be an exceptional source of biologically active compounds. Four compounds were isolated and identified, namely: dolastane diterpene new for the genus Padina; phaeophytin and hidroxy-phaeophytin new for the family Dictyotaceae, and; mannitol first described in this species. Saturated fatty acids as compared to the percentages of unsaturated fatty acids were shown to be present in greater abundance. Palmitic and linolenic acid were the main saturated and unsaturated acids, respectively. Cytotoxic and antioxidant activities were evaluated using human erythrocytes. In vivo evaluations of acute toxicity and genotoxicity were performed in mice. Methanolic extract of P.sanctae-crucis presented antioxidant activity and did not induce cytotoxicity, genotoxicity or acute toxicity. Since Padina sanctae-crucis is already used as food, has essential fatty acids for the nutrition of mammals, does not present toxicity and has antioxidant activity, it can be considered as a potential nutraceutical.

Toxicological, Antidiarrheal and Spasmolytic Activities of Solanum paniculatum.

Solanum paniculatum is popularly known as "jurubeba-verdadeira". In folk medicine, its roots, stems, and leaves are used as tonics, anti-inflammatories, carminatives, diuretics, and for gastrointestinal disorders. This species is listed in the Brazilian Pharmacopoeia and belongs to the "Relação Nacional de Plantas Medicinais de Interesse ao SUS". Based on folk medicine data of the Solanum genus, we decided to investigate whether the crude ethanol extract from S. paniculatum aerial parts presents toxicological, antidiarrheal, and spasmolytic activities. The crude ethanol extract from S. paniculatum aerial parts did not produce in vitro or in vivo toxicity and showed dose-dependent antidiarrheal activity, inhibiting equipotently both the defecation frequency (ED50 = 340.3 ± 35.1 mg/kg) and liquid stool formation (ED50 = 370.1 ± 19.4 mg/kg) in mice. Conversely, the crude ethanol extract from S. paniculatum aerial parts did not inhibit normal intestinal transit, even though it has shown a dose-dependent reduction of both the castor oil-induced intestinal transit (Emax = 36.9 ± 1.3 %, ED50 = 242.0 ± 8.6 mg/kg) and intestinal fluid content (Emax = 74.8 ± 2.4 %, ED50 = 328.9 ± 15.9 mg/kg). Additionally, the crude ethanol extract from S. paniculatum aerial parts was approximately 2-fold more potent in antagonizing the phasic contractions induced with histamine (IC50 = 63.7 ± 3.5 µg/mL) than carbachol 10(-6) M (IC50 = 129.3 ± 14.1 µg/mL). Therefore, we concluded that the crude ethanol extract from S. paniculatum aerial parts presents antidiarrheal activity in mice related to the inhibition of small intestinal motility and secretion as well as nonselective spasmolytic activity on the guinea pig ileum.

Chemical composition, antitumor activity, and toxicity of essential oil from the leaves of Lippia microphylla.

The chemical composition, antitumor activity and toxicity of the essential oil from Lippia microphylla leaves (OEL) were investigated. The major constituents were thymol (46.5%), carvacrol (31.7%), p-cymene (9%), and γ-terpinene (2.9%). To evaluate the toxicity of OEL in non-tumor cells, the hemolytic assay with Swiss mice erythrocytes was performed. The concentration producing 50% hemolysis (HC50) was 300 µg/mL. Sarcoma 180 tumor growth was inhibited in vivo 38% at 50 mg/kg, and 60% at 100 mg/kg, whereas 5-FU at 50 mg/kg caused 86% inhibition. OEL displays moderate gastrointestinal and hematological toxicity along with causing some alteration in liver function and morphology. However, the changes were considered reversible and negligible in comparison to the effects of several anticancer drugs. In summary, OEL displays in vivo antitumor activity and a moderate toxicity, which suggests further pharmacological study.

Assessment of mutagenic, antimutagenic and genotoxicity effects of Mimosa tenuiflora

Genotoxic effects of Mimosa tenuiflora (Willd.) Poir, Fabaceae, were investigated by using both micronucleus test and bacterial reverse mutation assay in Salmonella typhimurium TA97, TA98, TA100, TA102 respectively. In respect of Ames test results show that the extract does not induce mutations in any strains of Salmonella typhimurium tested since the mutagenicity index is less than 2. In the antimutagenic effect was observed that the extract at the concentrations tested significantly decreased the mutagenicity index of all strains tested which characterized the extract as antimutagenic in these conditions. In the micronucleus test in vivo, we observed that the concentrations used did not induce an increase in the frequency of micronucleus in normochromatic erythrocytes of mice. Therefore, we concluded that the extract of M. tenuiflora is not mutagenic in the absence of exogenous metabolizing system and does not induce an increase in the frequency of the micronucleus characterized as an agent not mutagenic in these conditions. Further studies of toxicity need to be made to the use of this plant in the treatment of diseases to be stimulated.

Avaliação da toxicidade aguda, efeitos citotóxico e espasmolítico de Pomacea lineata (Spix, 1827) (Mollusca, Caenogastropoda) / Evaluation of the acute toxicity, cytotoxic and spasmolytic effects of Pomacea lineata (Spix, 1827) (Mollusca, Caenogastropoda)

Pomacea sp. e sua desova têm uso popular para tratar diarréia e doenças respiratórias. Este trabalho objetivou avaliar a toxicidade aguda e os efeitos citotóxico e espasmolítico dos liófilos de Pomacea lineata e de sua desova. Os liófilos não apresentaram toxicidade aguda (até 2 g/kg v.o.) ou efeito citotóxico (até 1 mg/mL). P. lineata relaxou a traquéia pré-contraída com CCh na presença (Emax = 48,8 ± 6,4 por cento) e na ausência (Emax = 47,3 ± 9,1 por cento) de epitélio, já a desova relaxou apenas na presença (Emax = 36,3 ± 2,5 por cento) de epitélio. Os liófilos foram ineficazes sobre o tônus espontâneo da traquéia. P. lineata foi mais potente em inibir as contrações do íleo induzidas por ACh (logCI50 = 2,5 ± 0,04 µg/mL) que por hist. (logCI50 = 2,7 ± 0,04 µg/mL). A desova inibiu igualmente as contrações induzidas por ACh (logCI50 = 2,5 ± 0,02 µg/mL) e hist. (logCI50 = 2,5 ± 0,06 µg/mL). P. lineata foi mais potente em relaxar o íleo pré-contraído com ACh (logCE50 = 1,7 ± 0,12 µg/mL) do que com KCl (logCE50 = 2,4 ± 0,06 µg/mL) ou hist. (logCE50 = 2,2 ± 0,18 µg/mL). A desova relaxou equipotentemente o íleo pré-contraído com KCl (logCE50 = 2,3 ± 0,15 µg/mL), ACh (logCE50 = 1,9 ± 0,14 µg/mL) ou hist. (logCE50 = 2,2 ± 0,16 µg/mL), sugerindo um bloqueio dos CaV. P. lineata e sua desova apresentam efeito espasmolítico justificando a sua utilização no tratamento de diarréia e de doenças respiratórias.

Pomacea sp. and its eggs are used against diarrhea and respiratory diseases in folk medicine. The aim of this study was to investigate acute toxicity, cytotoxic and spasmolytic activity of lyophilized Pomacea lineata and its eggs. P. lineata and its eggs present no acute toxicity (until 2 g/kg p.o.) or cytotoxic effect (until 1 mg/mL). P. lineata and its eggs have no effect on guinea-pig trachea spontaneous tonus. P. lineata relaxed trachea pre-contracted with CCh in the presence (Emax = 48.8 ± 6,4 percent) and absence (Emax = 47.3 ± 9,1 percent) of epithelium, the eggs relaxed only in the presence (Emax = 36.3 ± 2.5 percent) P. lineata was more potent to inhibit contractions induced by ACh (logIC50 = 2.5 ± 0.04 µg/mL) than histamine (logIC50 = 2.7 ± 0.04 µg/mL). The eggs inhibited contractions induced by ACh (logIC50 = 2.5 ± 0.02 µg/mL) and histamine (logIC50 = 2.5 ± 0.06 µg/mL) in a non-selective manner. P. lineata was more potent in relax ileum pre-contracted with ACh (logEC50 = 1.7 ± 0.12 µg/mL) than KCl (logEC50 = 2.4 ± 0.06 µg/mL) or histamine (logEC50 = 2.2 ± 0.18 µg/mL). The eggs were equipotent in relax ileum pre-contracted with of KCl (logEC50 = 2.3 ± 0.15 µg/mL), ACh (logEC50 = 1.9 ± 0.14 µg/mL) or histamine (logEC50 = 2.2 ± 0.16 µg/mL), that is suggestive of the blockade of the voltage-operated calcium channels. Collectively, the results validate folk use of P. lineata and its eggs to treat diarrhea and respiratory diseases.